Known processes for producing an optically active .alpha.-hydroxycarboxylic acid having a phenyl group include optical resolution of racemates by crystallization or chromatography and asymmetric synthesis through organochemical procedures. These processes generally involve complicated operations, only to attain a low yield of a product.
To overcome these problems, biological processes utilizing microorganisms have been proposed. For example, it has been proposed to asymmetrically hydrolyze substituted or unsubstituted mandelonitrile or substituted or unsubstituted mandelamide by the action of a microorganism belonging to the genus Alcaligenes, Pseudomonas, Rhodopseudomonas, Corynebacterium, Acinetobacter, Bacillus, Mycobacterium, Rhodococcus or Candida to obtain optically active mandelic acid or derivatives thereof as disclosed in European Patent Publication No. 0 348 901 A (corresponding to JP-A-2-84198 (the term "JP-A" as used herein means an "unexamined published Japanese patent application")) and Applied and Environmental Microbiology, Vol. 57, pp. 3028-3032 (1991). It is also known to obtain a predominant proportion of R(-)-mandelic acid or a derivative thereof directly from racemic mandelonitrile or a derivative thereof by the action of a microorganism belonging to the genus Pseudomonas, Alcaligenes, Acinetobacter, Caseobacter, Nocardia, Bacillus, Brevibacterium or Aureobacterium, as disclosed in U.S. Pat. No. 5,223,416 (corresponding to JP-A-4-218385, JP-A-4-99495 and JP-A-4-99496).
In these biological processes, discovery of a new microorganism with higher activity and higher optical selectivity would produce a great industrial benefit.